Make your folders invisible without a software.

1)Right Click on the desktop.
Make a new folder

2)Now rename the folder with a blank space by holding ALT key and type 0160.

3)Now you have a folder without a name.

4)Right click on the folder>properties>customize.
Click on change icon.

5)Scroll a bit, you should find some empty spaces, click on any one of them.
Click ok.

Now drag this folder anywhere such as at the top right or centre such that nobody can guess a folder there.
Thats it, now you can store your personal data without any 3rd party tools